Composition and binder therefor



March 21, 1967 L. w. CORBETT ETAL 3,310,517

COMPOSITION AND BINDER THEREFOR Filed Sept. 20, 1965 Pressure Gauge 4 Fi/fer f Luke hf Corbett William .1. s am F'VT ATTORNEY United States Patent '0 3,310,517 COMPOSITION AND BINDER THEREFOR Luke W. Corbett, Mountainside, and William J. Sparks,

Westfield, N.J., assignors to Esso Research and Engineering Company, a corporation of Delaware Filed Sept. 20, 1965, Ser. No. 488,642 13 Claims. (Cl. 260-306) This application is a continuation-in-part of our patent application Ser. No. 234,872, which was filed on Nov. 1, 1962, and now abandoned.

The present invention relates to novel resinous binder compositions and to compositions comprising mineral aggregates and/ or fillers bonded with these novel resinous binder compositions.

More particularly, the instant invention relates to paving compositions of mineral aggregates, the particles of which are bound together by means of a novel resinous binder composition comprising (a) a styrene-acrylonitrile copolymer with a relatively high acrylonitrile content blended with (b) an alkylation polymer of a cyclopentadiene with a mononuclear aromatic hydrocarbon substantially free from olefinic and vinyl unsaturation, and with (c) a certain class of plasticizer. i

In a rior application Ser. No. 106,515, filed on May 1, 1961, and since abandoned, we disclosed paving aggregate binders composed of a styrene-acrylonitrile copolymer plasticized with plasticizing agents having viscosities of less than 2500 centipoise at 77 C. Such plasticizers were disclosed as generally higher boiling aromatic hydrocarbon fractions or the esters of aliphatic alcohols or phenols with mineral or organic acids, preferably dicarboxylic acids. These plasticized compositions have proven to be excellent binders for mineral aggregates, particularly where used for pavings which are employed in automobile service stations and airport loading areas and runways, for the principal reason that they have a relatively high resistance to the solvent action of jet fuels and other hydrocarbons, such as gasolines and lubricating oils which from time to time do spill and otherwise contact road and paving surfaces on highways, airports and the like.

When using a copolymer of styrene-acrylonitrile, wherein the acrylonitrile is present in relatively high percentage, i.e., more than and up to by weight, the resultant paving composition has even better resistance to jet fuels, aviation gasoline, aviation lubricating oils and the usual lubricants and fuels used and handled around airports, highways and service station areas. However,

er I

tent of the'cop'oly'mer and to obtain improved workability this way, but the resistance of the final paving composi tion to fuels and lubricating oils and the resistance to dissolution by these liquids is lowered markedly and the pavings so fabricated do not last long.

It has therefore been discovered and forms the crux of the instant invention that it is now possible to employ a relatively high percentage of acrylonitrile in the copolymer in order to achieve high fuel resistance in a final novel, resinous binder composition, and at the same time by employing certain amounts of plasticizer and alkylation polymer in the preparation of said composition, it will substantially retain fuel resistance without sacrificing unduly the Marshall stabilities of the paving compositions, and also concomitantly the compositions are provided with a sufiiciently low softening point so that they may be readily worked into and compounded with the mineral aggregates in equipment which is normally employed for similar operations where asphalt serves as the sole binder.

In short, the invention resides in a solution to the problem of how toprepare a binder composition having high solvent resistivity, e.g., particularly to jet fuels, while imultaneously possessing the ability to be easily worked and handled with conventional equipment. Thus, two antagonistic properties are reconciled in a completely unobvious manner. The achievement of this purpose is even more remarkable when, as will be detailed later herein, fairly large portions of the alkylationpolymer and plasticizer are necessary to create a composition of desired softening point, and these two components are both oil and fuel soluble. Thus, it is completely unexpected that the use of these two components with the copolymer containing a relatively high acrylonitrile content will result in a binder that is still oil and fuel resistant.

The quality and the proportions of the ingredients in the compositions of the present invention are critically different from the corresponding requirements in the ingredients that are used in mastic, or asphalt tiles. This appears clearly in comparisons of the flow sheet of asphalt tile manufacture and the flow sheet of paving manufacture as well as a comparison of the resulting compositions as brought out by the comparisons made in Tables I and II as follows.

i TABLE I Asphalt-Tile l-ianufacture Asphalt or Coumarone Resin Vegetable Asbestos Pitch Fillers Pigment Hot-Mi); Asphalt Paving Paving Course Asphalt Aggregate Fine Mineral Aggregate Filler Weighed .Batch J .1, Banbury Mixer v Two-Roll Mill Sheeting Roll Calender Line Cutter \l Stamp Press 4) Conveyor Curing Packaging From Abraham, H. Asphalts and Allied SubstancesHVol. :31, D. Van Nostrand, N.Y., 1962.

Monolithic in Place Structure From Asphalt Institute "The Asphalt Handbook," MS- l, College Park, 1461., 1962. I

As can be seen from the above table, the starting components and process sequencer for asphalt tile manufacture and for paving compositions are vastly different.

(From Traxler, R.N., Asphalt, Its Composition, Properties and Uses, Reinhold Publ. Co., N.Y., 1961.)

Specification properties of binder for asphalt tile:

Softening point, F. (R. & B.) 150-200. Penetration 77 F. (100 g., 5 sec.) 2-6. Penetration ratio, 39.2/77, percent No spec. Penetration 115 F. (50 g., 5 sec.) -25. Ductility 77 F. (5 cm./min.), cm. No spec. Thin film oven test 325 F., percent Orig. No spec.

(From Abraham, H., Asphalt and Allied Substances, 3, D. Van Nostrand Co., N.Y., 1962.)

Composition of asphalt or synthetic binder paving:

- Percent Binder (asphalt or synthetic binder) 4-12 Coarse aggregate (l /2" to #8 mesh) 15-50 Fine aggregate (#8 to 200 mesh) -85 Mineral filler (#140 minus) 0-10 (From Specifications and Construction Methods, -1, The Asphalt Institute, College Park, Md., 19 64.)

Specification properties of binder for paving:

Softening point, F. (R. & B.) -140. Penetration 77 F. (10 0 g., 5 sec.) 40-300. Penetration ratio, 39.2/77, percen 25 min. Penetration 115 F. (50 g., 5 sec.) No spec. Ductility 77 F. (5 om./min.),

om. min. Thin film oven test 3-25 F, percent orig. 50min.

(From Asphalt (for use in) Road and Pavement Construction, Federal Standard Stock Catalog, SS-A-706.)

It can be seen that the composition of asphalt tiles and asphalt tile binders are vastly different from paving compositions and paving binder compositions. Particularly noteworthy is the stark contrast between asphalt tile binder specifications and paving binder specifications. One skilled in the art of either pavings or tiles knows without equivocation that the two arts are not related in any man ner whatsoever.

It is well known, of course, that resins in general have many uses, e.g., in paint and varnish, in laminating wood, in paste for wall-paper and in molds for casting. However, the requirements for the various uses vary widely and special resin-s have to be formulated for particular uses. The resinous compositions of the present invention are useful where good resistance to oil and jet fuels and good flexibility are required.

The novel resinous binder blend is composed principally of the following polymers and co polyrners:

(1) A copolymer of a styrene with aorylonitrile or other monomer containing the group CH =CH-, such as acrylamide, acrylonitrile or vinyl methyl ketone. The styrene, of course, may be a hydrocarbon substituted styrene, i.e., a vinyl-substituted mononucle'ar aromatic compound, such as a vinyl toluene; but vinyl benzene, i.e., styrene, is generally employed. In our prior application we mentioned that the amount of acrylonitrile present would range from 1 to 40%, with the remainder of the copolymer being styrene. We have discovered, however, and we now prefer to employ, a copolymer which contains more than 10 wt. percent, preferably at least 13 to 20 wt. percent, and most preferably 15 wt. percent up to 20 wt. percent acrylonitrile, with the rest being a styrene, preferably vinyl benzene. These copolymers are prepared using the reactants and processes disclosed in US. Patent 2,97 0,978, which teaches that the proportion of acrylonitrile in the copolymers is between 5 and 10% for use in asphalt tile. Its disclosure is incorporated herein by reference.

(2) Various amounts of a polymer of an alkylation product prepared by alkylating a mononuclear saturated aromatic hydrocarbon, i.e., an aromatic hydrocarbon substantially devoid of olefinic and vinyl unsaturation, withdicyelopentadiene or cyclopentadiene or mixtures of these two, are blended in with the styrene-acrylonitrile copolymer. These blends comprise about 30 to 40 wt. percent of the styrene-acrylonitrile copolymer and about 60 to 70 wt. percent of alkylation copolymer. The method of preparing such alkylation polymers, together with reaction conditions and the reactants employed, catalysts and the like, is fully disclosed in United State-s Patent 3,023,200, the disclosure of which is concerned with the alkylation polymer as a thermoplastic resin useful in asphalt tile manufacture, and is incorporated in full into this specification by reference.

The term saturated aromatic hydrocarbon has the same meaning herein as stated in that patent. The cyclopentadiene alkylation polymer or dicyclopentadiene alkylation polymer as stated in that patent may be formed from the cyclo-C polyolefin and from xylene or an isomeric mixture of two or more xylenes, toluene, ethyl benzene, cu'mene, pcymene, anisole and various phenols and substituted phenols, as well as hydrocarbon streams contain ing aromatics and coming from overhead distillates or oils from Friedel-Crafts polymerization and cracked petroleum distillates. Preferred aromatics are mononu'clear aromatic hydrocarbons having from 7 to 10 carbon atoms having at least one. alkyl substituent. The most preferred alkylation polymers employed as a blend with the aforementioned styrene-acrylonitrile copolyrner are prepared from isomeric mixtures'of the xylenes, employing a mixture of monoand di-cyclopent'adiene, which is normally in equilibrium, as it is sold in commerce. The alkylation catalyst, as pointed out in the Epstein patent, U.S. Patent No. 3,023,200, patented Feb. 27, 1962, is aluminum chloride or another Friedel-Crafts type catalyst. The alkylation polymer is employed in an amount ranging between about and about 60 wt. percent, based on the final plasticized resin blend, preferably between about and 5 0% by weight. The exact amount of alkylation polymer blended into the aforementioned copolymer will depend to a considerable degree upon the amount of acrylonitrile originally employed in producing the copolymer and upon the amount of plasticizer added to the blend in compounding the binder for use with mineral aggregates. In any even-t, the softening point (ring and ball method) of the compounded binder blend, prior to admixing it with mineral aggregate and prior to plasticizing it, should have a softening point ranging between about 75 and about 145 C., preferably between about 110 and about 135 C.

(3) And a plasticizer.

Specific examples of these are tricresyl phosphate, diisooctyl phthalate, dioctyl phthalate, dihexyl phthalate, didecyl phthalate, butyl isooctyl phthalate, oxo-bottoms phthalate and the like. Some specialty compounds such as C; to C esters of tall oil acids, for instance, isooctyl tall-ate, butyl tallate and the like are also effective.

Other commercially known plasticizers such as high aromatic hydrocarbon fractions exemplified by catalytic cycle aromatic extracts, Z-chloroethyl phosphate, chlorinated biphenyl are not effective plasticizers for this invention since they derogate from the fuel resistance of the binder composition.

Useful plasticizers are aryl and alkyl aryl phosphates having from 12 to 36 carbon atoms and alkyl phthalates having from 4 to 36 carbon atoms in alkyl groups.

Plasticizers constituting oxo bottoms-phthalate which is prepared by using oxo bottoms which are ether alcohols, principally of C and higher average molecular weight, esterified with phthalic acid or phthalic anhydride and hereafter denoted as oxo bottoms-phthalate can be used. U.S. Patent 2,955,928, patented Oct. 11, 1960, and U.S. patents mentioned therein, discloses in detail the chemical identity of, and the method of preparing, oxo bottoms, U.S. Patent 3,054,666, patented Sept. 18, 1962, by Neblett et al., discloses oxo bottoms-phthalate (column 3, line 15) and elsewhere therein its method of preparation. The preparation method involves a conventional acylation or aroylation reaction.

Two of the best plasticizing agents are tricresyl phosphate and the 0x0 bottoms-phthalate. Oxo bottomsphthalates are particularly preferred since they are relatively less expensive than the other preferred plasticizer and are with the tricresyl phosphates the most effective. The amount of plasticizer employed in the binder composition, based on the binder composition, ranges be tween about 20 and about 40%, preferably between about 25 and about 35%, although the exact amounts of plasticizer used are those which will give the final binder composition a softening point between about 30 and about C., preferably between about 40 and about 65 C. Generally speaking, where the amount of acrylonitrile employed in the copolymer ranges as above stated and where the amount of alkylation ranges in amountsas above stated, the amount of plasticizer employed will range between about 25 and about 35 wt. percent based on the plasticized total binder composition. The preparation of such binder composition having such softening points has been found desirable in order to allow for the practical handling of large quantities of commercial size mineral aggregates and binder in the mixing equipment normally employed in compounding asphalt-mineral aggregate paving compositions preparatory to laying or repairing roadways, airports and other surfaces used for automobile, truck and airplane traffic.

The alkylation copolymer is generally prepared using a mononuclear aromatic hydrogation to dicyclopentadiene weight ratio of from about 2:1 up to about 9: 1. Preferably, Weight ratios in the upper range between 7:1 and 10:1, i.e., higher amounts of aromatic hydrocarbons are used because they result in alkylation polymer having the lower softening points as compared to the use of more nearly equal amounts of the two reactants, wherein relatively high softening points are obtained in the alkylation copolymer. A preferred specific ratio involves the use of about 10 parts of dicyclopentadiene and about parts of xylene. This produces a resin, having a softening point of around 40 C' by the ball and ring method, which, when blended with a copolymer resulting from the reaction of 15 parts acrylonitrile and 85 parts of styrene in the ratio of 1 part copolymer to 2 parts of alkylation polymer in unplasticized condition, yields a blend having a softening point of about C. Other weight ratios of the two polymers may be employed so long as when plasticized the final binder has a softening point of between about 30 and 80 C. measured by the ball and ring method.

The mineral aggregates employed in compounding the paving compositions are those which are typical and conventionally employed. Mineral aggregates as the term is used herein are those materials that are used conventionally in combination with asphalts to prepare paving mixes for a wide variety of purposes. Generally, they have a continuous grading within the range of 2 /2 maximum to passing a #200 mesh sieve, although the largest size component can vary from about /2" to about #8 mesh sieve. Most commonly used materials are broken stone, slag, crushed or uncrushed gravel, sand, and mineral fillers. Aggregates are characterized by sieve analysis to regulate particle size, abrasion to evaluate wear, soundness to evaluate weathering, sand equivalent to measure detrimental or clay-like material and water absorptionto indicate any swelling tendencies. Since aggregates normally consist of 88% or more of paving mixtures, their properties are of utmost importance in a paving application. Reference is hereby made to numerous publications dealing with the types of aggregates customarily employed in paving surface and substrate compositions, for example, the publication by the Asphalt Institute entitled, Specifications and Construction Methods for Hot-Mix Asphalt Paving for Streets and Highways, first edition, May 1957, lists Types I through VIII as typical types of aggregate particles size distribution masses. The substance forming the aggregates can be of any convenient conventionally employed type, such as trap rock, gravel, slag, sand filler, dust or limestone, and in accordance with the specifications mentioned and set forth in the above-described publication, range in size from /2 in diameter in certain proportions down to 100 mesh in diameter and less. A typical mineral aggregate mixture would contain tra rock comprising 30 parts by wt. of /2 to /s" in diameter, 65 parts by wt. of sand of 100 mesh and coarser in diameter and up to parts by wt. of limestone mineral dust. Another typical mineral aggregate mixture employed is known as Type VI and is composed of the following:

Trap rock percent 40 Gravel sand do 55 Limestone dust do 5 Diameter of particles inch /2 to .001

In general, the binder composition of the invention is incorporated into a paving composition in amounts ranging between about 4% of the total mixed paving composition u to about 12% by wt. of the total paving composition, preferably between about 5 wt. percent and about wt. percent. The paving composition must have a Marshall stability at 140 F. at least as high as that of good asphalt pavement, i.e., at least 500 lbs., but not too high, e.g., not more than 3000 lbs., so as to avoid being too brittle when cold. The Marshall flow at 140 F. should not exceed 18 one-hundredths of an inch.

Critical requirements for the plasticized binder composition include a softening point between and 80 C. and a resistance to attack by jet fuel. In order to meet all the requirements, the two resins used, namely, the copolymer and the alkylation polymer, must be in ratio bet-ween 30/70 and /60. The copolymer must have more than about 10% but not more than about 20% acrylonitrile; and the alkylation polymer must have not less than about-9% but not more than about 14% of a cyclopentadiene.

The paving compositions can be compounded or admixed by either a conventional manufacturing technique or a special technique adapted for the novel compositions of the invention. Conventionally, a pug mill type mixer containing preheated aggregate has added to it preheated plasticized and liquefied resin composition, the composition having previously been preheated to a sufiiciently high temperature to enable it to be readily poured and admixed with the preheated aggregate. Usually the aggregate and binder composition are admixed at a temperature ranging between about 200 F. and about 400 F.

Another method of preparing paving compositions, considered to be unique for synthetic resin binders as described herein, has been demonstrated numerous times during the development of this invention. The method involves the use of the same conventional equipment and the same procedure except that the aggregate is pre heated to 350400 F. (normally 300-350 F.). To the aggregate in the pug mill is just added the cold resin or polymer blend in a flake or pellet form; followed by the addition of the plasticizers. The cold resin is immediately blended into the hot aggregate by the mixing action of the pug mill. The heat of the aggregate causes the resin to melt and then to be fluxed with the plasticizers added thereafter. This addition part of this operation takes from 15 to 30 seconds, with mixing continued up to a total of -90 seconds to complete uniform coating of the aggregate, after which the mix is ready for transferring to the lay-down or placing equipment. The higher temperature of the aggregate is taken up as heat of fusion of the resin polymer. This is just another means of making the same paving composition but it takes advantage of the granular form of the resin and the pourable liquid form of the plasticizer thus obviating the need of hot binder storage.

The mixing and laying equipment customarily employed, when working with asphalt as a binder, is employed in preparing and placing the present improved compositions. See Design and Construction of Asphalt Pavements by Wallace and Martin, 1958 edition, published by McGraw-Hill Book Co., NY. Once the coating of binder on the mineral aggregate particles has been accomplished through thorough mixing, a uniform distribution of the ingredients, which may also include some small amount (5%) of hydrocarbon oil, based on the binder portion of the mixture, with or without the oil being first formed into a pigment paste for desired coloration, the aggregate materials are firmly laid in courses in preparing new road construction or resurfacing old roads. However, the primary need for the oil is to incorporate the color pigment in the paving composition. Thus, not only are the paving compositions of the invention highly resistant to fuels, but they also can be colored. There is noting critical about the order of addition of the various bonding materials, except that it is necessary that the relative amounts of copolymer, alkylation polymer, and plasticizer are employed to give a final product having a sufficiently low viscosity to permit ready workability of the plasticized blend at the temperatures employed during the mixing operation. If desired, the oil-pigment paste mix may be contained in polyethylene or polypropylene bags, and the entire bag, i.e., contents and container, may be added to the mixer, since it has been found that polyethylene and polypropylene may be readily blended into the mix and form part of the binder composition. Generally speaking, the amount of hydrocarbon oil, such as a lubricating oil, is kept at a minimum in order to minimize the petroleum solubility characteristics of the paving composition ultimately-laid down.

The following examples, the parts mentioned therein being by weight, are illustrative of the character of the invention, but it is not intended that the invention be limited thereto.

Example 1 Starting with a mixture of 15 parts of acrylonitrile and parts of styrene, a copolymer was prepared as set forth in US. Patent No. 2,970,978 and a mixture of isomeric xylenes in the amount of parts was alkylated and polymerized with 10 parts of dicyclopentadiene to produce an alkylation polymer as shown in Patent No. 3,023,200. A resinous blend of 35% of copolymer and 65% of alkylation polymer was prepared. To this there was added sufiicient tricresyl phosphate to give a final plasticized resin blend containing 30% tricresyl phosphate. A type V mineral aggregate of trap rock, sand and limestone filler was then admixed with the plasticized resin blend to give a final compounded paving composition of 93% aggregate and 7% binder. Hereinafter this composition will be denoted as composition A.

A second resin blend was also prepared in a manner identical to that previously described, except the blend itself was prepared from a copolymer of 7% acrylonitrile and 93% styrene and from an alkylation polymer containing as reactants 90% xylene and 10% dicyclopentadiene. The two resins were mixed in the ratio of 55 parts of the copolymer. and 45 parts of the alkylation polymer. In all other respects, the same compositions and the same final bonded paving aggregate were made up as previously described in this example. The composition is hereinafter denoted as composition B.

A paving composition C was prepared, using the same amounts and same methods of fabrication as in connection with paving compositions A and B, except that the resin blend was prepared as follows: 10 parts of acryl onitrile were combined with 90 parts of styrene and 90 parts of a mixture of xylene isomers were alkylated with 9 parts by wt. of dicyclopentadiene to give the alkylation polymer. The blend comprised 70 parts of copolymer and 30 parts of alkylation polymer.

Compositions A, B and C were subjected to a standard fuel resistance test after having been prepared in briquette form.

The test can be further understood by reference to the apparatus designed and developed for carrying it out. In this apparatus, oil burner pump 1 pumps the fuel or solvent from steel box 2 which serves as a fuel reservoir through line 3 and filter 4 and around through line 5 to ,four oil fuel burner nozzles mounted in assembly 6 which directs a spray of the fuel to the bottom of briquette 7 through a hole 8 at the top of fuel reservoir 2. The fuel hits the bottom of the briquette with considerable force and falls to the bottom of the fuel reservoir 2 where it is pumped around for reuse. The briquette is a Marshall briquette (ASTM 1559-60T) of 4" in diameter and has a height of 2.5".

Duplicate test specimens are weighed to the nearest half gram and then submitted to the continuous spray action of the fuel or solvent at a pressure of 80 p.s.i.g., with each nozzle discharging 2.5 -g.p.h. At one hour intervals each specimen is withdrawn and immediately hand brushed with 50 strokes of the wire brush. The specimen is then reweighed, returned to the apparatus and again submitted to the spray action. This process is repeated at one hour intervals until of the exposed surface of the briquette has been removed. This represents the sol vent resistance, in hours, shown in the following table:

1 JP4 contains: 18.2% aromatic hydrocarbons; 81.1% saturated hydrocarbons; 0.7% olefinie hydrocarbons.

It can be seen from the above table that the composition containing. the oopolymer with parts of acrylonitrile had the highest solvent resistance properties. It should be mentioned that typical briquettes with actual asphalt binder have a fuel resistance in this test of about an hour.

Further tests of additional specimens of Marshallbriquettes were subjected to a standard Marshall stability test (ASTM D-1559-60T) with the following results:

A is the preferred composition. The ingredients in 100 parts of binder are in the ratios of 24.5/45.5/ 30 for copolymer/alkylation polymer/plasticizer. The copolymer has 15% acrylonitrilef The alkylation polymer has 10% dicyclopentadiene. The ratio of copolymer/alkylation polymer is 35/65.

Example 2 The same compositions as described with respect to paving compositions A, B and C were prepared, using a mineral aggregate type VI mix, and in each case tricresyl phosphate was employed as the plasticizing composition. In compositions D and E the same resin blend was employed as in composition A and in both instances tricresyl phosphate was employed as the plasticizer. In composition D, 25% of the final plasticized composition was plasticizer and in composition E, 29% was plasticizer. The same 7% binder-93% mineral aggregate Marshall briquettes were compounded and tested for Marshall stability and percent voids. Also, paving compositions F and G were prepared using the same resin blend as was used in paving composition B, except that in composition F, the final plasticized binder composition contained 25% tricresyl phosphate and in composition G it contained 29% of tricresyl phosphate. The following Marshall stability results were obtained:

Example 3 Marshall briquettes of type V mineral aggregate, using 7% plasticized resinous blends were again made up, using thesame resin blends as employed in compositions A and B. In all cases, the final plasticized resinous blend contained 71% resin blend and 29% tricresyl phosphate.

Compositions H and I used the same resin blend as composition A and compositions K and L used the same resin blend as was used in composition B. The type V mineral aggregate employed in making up the Marshall briquettes in compositions H and K was a type V mineral aggregate of New Jersey trap rock, concrete sand, and limestone filler, and the type V aggregate employed in making up compositions J and L was composed of New York limestone and limestone screenings. Here again, as in previous examples, the final binder-mineral aggregate paving composition contained 7% binder. The following Marshall stability and flow and fuel resistance in hours in accordance with the same ASTM procedures as heretofore stated, were obtained:

From the above data, it can readily be seen that the resin blend employed in compositions H and J, although having a somewhat lower Marshall stability, nevertheless had a far higher Marshall stability when bound with the particular resin blend than asphalt would have had under comparable conditions (about 575 to 600 lbs. for asphaltic binder). Nevertheless, their fuel resistance was quite high, being respectively 70 hours and 56 hours. It also will be noted that compositions K and L, although having a higher Marshall stability, had considerably lower fuel resistance. This is because of inherent incompatability of the binder with these solvent type fuels.

1 1 Example 4 Approximately 2 tons of mineral aggregate comprising 49% of A" trap rock, 49% #6 sand, and about 2% limestone filler was admixed. It had the following screen analysis.

Percent Passing /s" 100 Passing #4 mesh 93 Passing #8 mesh 48 Passing #1 6 mesh 38 Passing mesh 31 Passing #50 mesh 21 Passing #100 mesh 9 Passing #200 mesh 3 A binder was prepared comprising one part by weight of a styrene-acrylonitrile copolymer prepared from 85% of styrene and 15% of acrylonitrile admixture and two parts by weight of an alkylation polymer of 10% of dicyclopentadiene and 90% of an isomeric mixture of xylenes. Sufficient tricresylphosphate was added to this resin blend to give a tricresyl-phosphate and 65% resin blend admixture.

Sufiicient plasticized resin blend binder at a temperature of between about 325 and about 400 F. was added to the 2 tons of aggregate maintained by preheat treatment at a temperature of about 400 F. in a pug mill to give 7% by Weight of binder in the mix and so that the mix became homogeneous at about 310 F. after which it was loaded into trucks and was spread at the road construction site at a temperature of about 275 F., initially rolled and compacted in place at about 225 F. and rerolled and finally completely compacted at a temperature of about 160 F. The total time from the initial pug mill mixing to final rolling was about 110 minutes.

Marshall briquette tests showed that the aggregatebinder composition laid down as above described had the following characteristics:

Marshall stability at 140 F., lbs 850 Marshall flow at 140 F., 0.01" 12 Percent voids 5.0

tion. The resins and plasticizers used in the compositions correspond to the following keys and symbols.

Plasticizer component:

TCPTricresyl phosphate.

DIOP-Di-isooctyl phthalate.

DOP-Di-octyl phthalate.

OBP-0x0 bottoms-phthalate.

DDPDidecyl phthalate.

CBPCh1orinated biphenyl. CEP2-chloroethyl phosphate. IOT-Iso-octyl tallate.

CCECat. cycle aromatic extract (hydrofined).

TABLE VII.PROPERTIES OF SYNTHETIC BINDER (6%) MIXES MADE WITH VARIOUS TRICRESYL PHOSPHATE (TOP)- RESIN COMPOSITIONS USING ASPHALT INSTITUTE TYPE V AGGREGATE Resin Composition M N O P Q R s T U Resin/TOP 75/25 Marshall Stability 2 at 140 F., lbs 1, 430

Fuel Resistance, hrs .1 10 Resin/TOP 70/30 Marshall Stability at 140 F., l 720 Fuel Resistance, hrs 22 Resin/TOP (35/35 Marshall Stability at 140 F., lbs 810 985 1, 450 880 900 1, 100 775 1,500 Fuel Resistance, hrs t 13 21 37 33 100+ 1 0+ 1 Asphalt Institute SS-l, June 1964.

2 ASTM D 1559-621.

3 Mix too stiff to handle.

4 Described in Example 1 with respect to the drawing.

Example 5 In this example, various binder compositions were prepared and then tested under different conditions to further As can be seen from the above Table VII that when the amount of acrylonitrile in the copolymer is 15%, only a relatively small quantity of the copolymer is required, thus allowing the use of greater quantities of the relatively less illustrate the advantages of the compositions of the invenexpensive alkylation copolymer.

TABLE VIII.PROPERTIES OF SYNTHETIC BINDER (0%) MIXES MADE WITH VARIOUS RESIN'PLASTICIZER COMPOSI- TIONS (ALL AT /30 PROPORTION) USING ASPHALT INSTITUTE TYPE V AGGREGATE 1 Resin Composition N i N 0 0 O l P l P R S S S T Plasticizer DIOP DDP DOP OBP CEP DDP DOP OEP OBP CEP CCE OBP Marshall Stability 2 at F., lbS 1, 600 1, 1, 400 2, 150 1, 315 700 1, 215 1,250 755 785 1, 000 2, 250 Fuel Resistance, hrs .t 40 30 65 10 50 20 64 11 100+ 11 20 100 1 Asphalt Institute SS-l, June 1964. 2 ASTM D 1559-62T. 3 Described in Example 1 with respect to the drawing.

13 Prom t he above data tabulated in Table VIII, it can be seen that oxo bottoms-phthalate is a particularly effective plasticizer in that it does not affect the fuel resistance of the total composition. Conventional plasticizers such as of 2% inches to passing a #200 mesh sieve and, (b) 4 to 12 parts by weight of the composition of claim 1. S. A method as in claim 7 wherein the alkylation poly- 2-chloroethyl phosphate, catalytic cycle aromatic extract mer is prepared from dicyclopentadiene and at least one and chlorinated phenol are not effective.

xylene.

TABLE IX.QUALITATIVE COMPARISON OF RESIN-TRICRESYL PHOSPHATE (70/30) BINDERS WHEN A 3 x 1" x 54; STRIP WAS IMMERSED IN 1P4 FUEL Resin Composition N O R l S Conditionof Strip After Immersion:

Consistency, 1 hr Sottened softened S1. soft No change. Consistency, 24 hrs Showed flow Showed flow. Sl. flow. Do. Showedsolubility, hrs. 3 3 8 16. Gen al condition, 24 hrs Very soit Very soft Soft Very good.

The data in the above Table IX shows that this copolymer with acrylonitrile is twice as efiective in reducing the'solubility of a binder composition as the coploymer with 10% acrylonitrile.

Having now thus fully described and illustrated the character of the invention, whereby improved resinous compositions are obtained that have good resistance to fuels without incurring the usually attendant disadvantages of excessively high softening point and excessive brittleness at l'ow temperatures, what is desired to be secured by Letters Patent is:

1. An improved fuel resistant resinous composition suitable for use as a binder in highly fuel resistant paving compositions consisting essentially of a homogeneous blend of c (a) 60 to 80 wt. percent of a resin blend comprising (1) 30 to 40 wt. percent of a copolymer of 80 to less than 90 parts by weight of styrene and more than 10 and up to parts by weight of acrylonitrile,

(2) 60 to 70 wt. percent of an alkylation polymer of 2 to 9 parts by weight of dicyclopentadiene or cyclopentadiene per part by weight of a C to C mono-nuclear aromatic compound having at least one alkyl substitutent,

(b) 20 to 40 wt. percent of a plasticizer selected from the group consisting of aryl and alkylaryl phosphates having 12 to 36 carbon atoms and alkyl phthalates having from 4 to 36 carbon atoms in the alkyl groups and,

wherein said homogeneous blend has a softening point between about 30 to 80 C.

2. A composition as in claim 1 wherein the alkylation polymer is prepared from dicyclopentadiene and at least one xylene.

3. A composition according to claim 1 wherein said plasticizer is tricresyl phosphate.

4. A composition according to claim 1 wherein said plasticizer is oxo-bottoms phthalate.

5. A composition according to claim 1 wherein said amount of acrylonitrile is about 15 wt. percent, said alkylation copolymer is made from dicyclopentadiene and said plasticizer is oxo-bottoms phthalate.

6. A composition according to claim 1 wherein said amount of acrylonitrile is about 15 wt. percent, said alkylation copolymer is made from dicyclopentadiene and said plasticizer is tricresyl phosphate.

7. An improved fuel resistant paving composition comprising a mixture of (a) 88 to 96 parts by weight of a mineral aggregate having a continuous or skip grading within the range 9. A method according to claim 7 wherein said plasticizer is tricresyl phosphate.

10. A method according to claim 7 wherein said plasticizer is oxo-bottoms phthalate.

11. A method according to claim 7 wherein said amount of acrylonitrile is about 15 wt. percent, said alkylation copolymer is made from dicyclopentadiene and said plasticizer is oxo-bottoms phthalate.

12. A method according to claim 7 wherein said amount of acrylonitrile is about 15 wt. percent, said alkylation copolymer is made from dicyclopentadiene and said plasticizer is tricresyl phosphate.

13. A method of preparing a fuel resistant paving composition comprising the steps of:

(a) preparing particles from a resin blend comprising (1) 30 to 40 wt. percent of a copolymer of to less than parts by weight of styrene and more than 10 and up to 20 parts by weight of acrylonitrile, and

(2) 60 to 70 wt. percent of an alkylation polymer of 2 to 9 parts by weight of dicyclopentadiene or cyclopentadiene per part by weight of a C to C mono-nuclear aromatic compound having at least one alkyl substitutent,

(b) adding said particles to an agitated mineral aggregate having a continuous or skip grading within the range of 2 /2 inches to passing a #200 mesh sieve heated to a temperature of from 350 to 400 F. and,

(0) adding 20 to 40 wt. percent of a liquid plasticizer based on the total weight of said resin blend and said plasticizer wherein said plasticizer is selected from the group consisting of aryl and alkylaryl phosphates having 12 to 36 carbon atoms and alkyl phthalates having from 4 to 36 carbon atoms in the alkyl groups.

References Cited by the Examiner UNITED STATES PATENTS FOREIGN PATENTS 919,490 2/1963 Great Britain. 953,989 4/1964 Great Britain.

MORRIS LIEBMAN, Primary Examiner.

B. A. AMERNICK, Assistant Examiner. 

1. AN IMPROVED FUEL RESISTANT RESINOUS COMPOSITION SUITABLE FOR USE AS A BINDER IN HIGHLY FUEL RESISTANT PAVING COMPOSITIONS CONSISTING OF A HOMOGENEOUS BLEND OF: (A) 60 TO 80 WT. PERCENT OF A RESIN BLEND COMPRISING (1) 30 TO 40 WT. PERCENT OF A COPOLYMER OF 80 TO LESS THAN 90 PARTS BY WEIGHT OF STYRENE AND MORE THAN 10 AND UP TO 20 PARTS BY WEIGHT OF ACRYLONITRILE, (2) 60 TO 70 WT. PERCENT OF AN ALKLYATION POLYMER OF 2 TO 9 PARTS BY WEIGHT OF DICYCLOPENTADIENE OR CYCLOPENTADIENE PER PART BY WEIGHT OF A C7 TO C10 MONO-NUCLEUR AROMATIC COMPOUND HAVING AT LEAST ONE ALKYL SUBSTITUENT, (B) 20 TO 40 WT. PERCENT OF A PLASTICIZER SELECTED FROM THE GROUP CONSISTING OF ARYL AND ALKYLARYL PHOSPHATES HAVING 12 TO 36 CARBON ATOMS AND ALKYL PHTHALATES HAVING FROM 4 TO 36 CARBON ATOMS IN THE ALKYL GROUPS AND, WHEREIN SAID HOMOGENEOUS BLEND HAS A SOFTENING POINT BETWEEN ABOUT 30* TO 80*C. 